Materials and methods for components of lithium batteries

ABSTRACT

The present invention relates to materials and methods for components of lithium batteries, such as metal anodes having a protective coating.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/433,944, filed on Jun. 6, 2019, which claims benefit of the filingdates and rights of priority to U.S. Provisional Application No.62/681,674, filed on Jun. 7, 2018, U.S. Provisional Application No.62/728,744, filed on Sep. 7, 2018, and U.S. Provisional Application No.62/756,010, filed on Nov. 5, 2018, which are incorporated by referenceherein.

FIELD

The present invention relates to anodes, cathodes and other componentsof lithium batteries.

BACKGROUND

Lithium batteries have superior electrochemical capacity, high operatingpotential and great charge and discharge cycles. Demand for lithiumbatteries is increasing in the fields of portable information terminals,portable electronic devices, small power storage devices for home use,motorcycles, electric cars, hybrid electric cars, and the like. Hence,improvements to the performance and the safety of lithium battery aredesired in response to the increasing demand of such applications.

Conventional lithium batteries using a graphite anode are reaching tothe theoretical capacity, leaving little room for the performanceimprovement. Such problems pertaining to use time of batteries come tothe fore as electric cars are becoming popular.

In order to improve the energy density performance, thorough research isthus ongoing these days into lithium metal batteries using a lithiummetal as the anode of lithium-ion batteries. However, the lithium usedpossesses potential safety issues, especially paired with liquid organicelectrolytes that are flammable and have been used for years.Lithium-free anodes, which comprising copper as the anode, havingadvantages of high energy density and great safety, compatible withcurrent manufacturing processes and low prices, are receiving attentionas next-generation battery materials.

A lithium-ion battery is configured to include a cathode, an electrolytelayer and an anode with a separator in which the electrolyte layerpossesses high ionic conductivity and low electronic conductivity. Thecathode can contain lithium-ion or lithium-free material, and the anodecan be the same comprising lithium-ions or lithium-free materials whilelithium-ions have to contained in either of the cathode or the anode forthe lithium-ion batteries. The currently commercial anode is graphite.However, the graphite is reaching to the theoretical capacity and leaveslittle room for the improvement. Lithium metal is considered as the“holy grail” of next-generation anodes due to its ultrahigh capacity(3,860 mAhg-1) and high negative potential (−3.04 V compared to standardhydrogen electrode).

However, the use of lithium metal in rechargeable batteries posesseveral major problems. First, when a lithium-metal battery discharges,lithium ions separate from the surface of the anode and travel to thecathode. When the battery is charged the same ions travel back anddeposit onto the anode as lithium metal. But instead of forming a nicesmooth coating on the anode, lithium metal has the tendency to generate“dendrites” chains of lithium atoms growing from the surface of theanode, which look like the roots of a tree. The dendrites grow biggerwith each charge-discharge cycle, eventually reaching the cathode andcausing the battery to short, leading to battery failure and potentialfires. Second, lithium metal is highly reactive, which means it suffersside reactions with the battery's liquid electrolyte, which is itself anenergy-rich medium. These undesirable reactions reduce the amount oflithium available and worsen the battery's life with everycharge-discharge cycle. Third, lithium batteries may suffer from lowCoulombic efficiency (CE), due to the parasitic reactions betweenlithium and electrolyte to form solid electrolyte interphase (SEI),leading to the continuous loss of lithium and increased resistanceassociated with electrolyte consumption and eventual batteries failure.

Since lithium is reactive with moisture, oxygen and nitrogen, itinevitably increases the cost of manufacturing. Even if somehow thecosts could be reined in, such as incorporation of a pin-hole freecoating on the anode, batteries with lithium metal inside are hard topass safety tests when using current liquid organic electrolyte that isflammable. These tests are designed to put the battery in extreme, butreal-life, conditions: piercing a nail into the battery (which mighthappen in a car accident) or heating it to more than 50° C., or 122° F.(a temperature that the interiors of cars or drones can easily reach) toultimately melt down the polymer separator. To circumvent the safetytest and not manufacture lithium metal anodes, this disclosure employscopper foil or other substrate as the starting anode with no lithiummetal inside. In such way, the battery is manufactured in the exact sameway as a conventional lithium-ion battery, including using a liquidelectrolyte, a widely available cathode comprising lithium-ions and ananode that begins its life as a copper sheet or other substrates.

Qian et al. disclosed a method of highly concentrated electrolytecomposed of 1,2-dimethoxyethane (DME) solvent and a high concentrationof the LiFSI salt for an anode-free cell design (Cu vs. LiFePO₄). Theyalso found that the cycle life of these cells can be extended whencycled with an optimized charge-discharge protocol. However, the cellfails at about 20 cycles. See Qian et al., Anode-Free RechargeableLithium Metal Batteries, Adv. Funct. Mater. 2016, 26, 7094-7102.

The target for such technology should at least last for 50 cycles beforethe capacity of batteries degrades below 80%. Therefore, there is stilla need to develop a more advanced lithium-metal free anode forlithium-ion batteries.

Elam et al. US Pat. App. Publication No. 20190044151 discusses a hybridprotective coating which includes an inorganic component and an organiccomponent such that the inorganic component includes at least one of ametal oxide, a metal fluoride, or combination thereof, and the organiccomponent includes at least one metalcone.

Some currently available batteries employ graphite and silicon/carbon asthe anode. However, graphite has a theoretical capacity of only 372mAh/g and it is reaching its theoretical capacity, leaving noimprovement room for future battery systems. As for the silicon/carbonbatteries, although silicon has a theoretical capacity of 3580 mAh/g,the volume change (expansion and contraction) is 400% upon charge anddischarge processes; However, the battery in pouch cells used in themilitary batteries, including batteries of drone and consumerelectronics can only tolerate about 10%. This limits the mass loading ofsilicon in the anode and is not competitive with lithium anodes.

Hu et al. US Pat. App. Publication No. 20160293943 discusses a batterystructure with a cathode, an electrolyte, and a lithium metal anodecoated with a composite coating including a mixture of a polymer and areinforcing fiber. The cathode and the lithium metal are held apart by aporous separator soaked with the electrolyte. The reinforcing fiber isdispersed in the polymer matrix. The composite coating is porous ornon-porous. The composite coating conducts lithium ions. The reinforcingfiber is chemically functionalized.

Cho et al. US Pat. App. Publication No. 20160372743 discusses a lithiummetal anode which includes a lithium metal layer and a multi-layerpolymer coating disposed over the lithium metal layer. The multi-layerpolymer coating includes a first outer polymeric crosslinked gel layerpositioned for contact with a battery electrolyte and a second innerpolymer layer disposed between the lithium metal layer and the firstouter polymeric crosslinked gel layer. The first outer polymericcrosslinked gel layer includes a first polymer, a soft segment polymer,and an electrolyte. The second inner polymer layer includes a secondpolymer. The second inner polymer layer provides mechanical strength andserves as a physical barrier to the lithium metal layer.

SUMMARY

As one aspect of the present invention, a metal anode having aprotective coating is provided. The metal anode comprises a metal layercomprising lithium, sodium, or potassium; and a protective coating onthe metal layer. The protective coating comprises a composite material,and the composite material comprises an oxide or fluoride of lithium,sodium, or potassium.

As another aspect, the present invention provides a lithium-free metalor carbon electrode for a lithium ion battery. The electrode comprises ametal or carbon layer and a protective coating on the metal layer. Theprotective coating can comprise aluminum oxide, titanium oxide, hafniumoxide, or one of the other materials described herein, including anycombination thereof.

As another aspect, a method is provided for preparing an anodeconfigured for use in a lithium-ion battery. The method comprisesdepositing a coating material on a metal substrate by atomic layerdeposition (ALD), chemical vapor deposition (CVD), plasma enhancedchemical vapor deposition (PECVD), sputtering, physical vapor deposition(PVD), plasma enhanced atomic layer deposition (PEALD), spinningcoating, dip coating, pulsed laser deposition (PLD), or any combinationthereof. The coating material is dielectric and lithium-ion conductive.

As yet another aspect, a cathode comprising a metal layer is provided.The cathode has a surface and comprises a lithium-based material. Thecathode also comprises an inert material on the surface of the metallayer. The cathode is configured for use as the cathode of a lithium-ionbattery or lithium-sulfur battery. The present disclosure also providesa process for preparing cathodes comprising depositing a thin layer ofthe inert material onto the surface of the metal layer by atomic layerdeposition, plasma enhanced atomic layer deposition, chemical vapordeposition, plasma enhanced chemical vapor deposition, sputtering,physical vapor deposition, spinning coating, dip coating, or pulsedlaser deposition.

As another aspect, a method of preparing a thin layer comprising lithiumis provided. The method comprises a) applying one or more interlayermaterial onto a substrate to form an interlayer material coatedsubstrate; b) heating the interlayer material coated substrate to anelevated temperature; and c) applying one or more metal layers onto theinterlayer material coated substrate, wherein the metal layer compriseslithium.

As another aspect, an electrode is provided for a lithium ion battery.The electrode comprises a metal layer; and a protective coating on themetal layer, wherein the protective coating comprises hafnium oxide,lithium hafnium oxide, a lithium fluoride-lithium carbonate composite,or a combination thereof. The metal layer can be lithium, copper oranother metal. The protective coating can be formed by atomic layerdeposition or plasma enhanced atomic layer deposition.

As another aspect, a method is provided for preparing a coated lithiumlayer. The method comprises depositing a coating material on a lithiumlayer by a roll-to-roll process, extrude printing or 3D printing.

These and other features and advantages of the present methods andcompounds will be apparent from the following detailed description, inconjunction with the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows the capacity of coin cells of Example 1 at 0.2 C, whereinthe coin cells comprise ˜5 mAh/cm² LiNiMnCoO₂ (Ni:Mn:Co=5:3:2),represented by NMC532, as the cathode and HfO₂ coated Cu as the anode.FIG. 1B shows the capacity of coin cells of Example 1 at 0.2 C, whereinthe coin cells comprise ˜5 mAh/cm₂ LiNiMnCoO₂ (Ni:Mn:Co=5:3:2),represented by NMC532, as the cathode and bare Cu as the anode.

FIG. 2 shows the capacity retention rate of coin cells which comprise ˜5mAh/cm² LiNiMnCoO₂ (Ni:Mn:Co=5:3:2), represented by NMC532, as thecathode and HfO₂ coated Cu as the anode. The data are for Example 1 at0.2 C.

FIG. 3 shows the Coulombic efficiency of coin cells which comprise ˜5mAh/cm² LiNiMnCoO₂ (Ni:Mn:Co=5:3:2), represented by NMC532, as thecathode and HfO₂ coated Cu as the anode. The data are for Example 1 at0.2 C.

FIGS. 4A, 4B and 4C show charge-discharge performance of batteries with˜4.8 mAh/cm² LiNiMnCoO₂ (Ni:Mn:Co=8:1:1), represented by NMC811, and 7nm HfO₂ coated Cu or bare Cu. The batteries were discharged at 0.33 Cand charged at 0.1 C at 55° C. after the first three cycles at 0.1 C.These data are for Example 1. (a) Cycling performance of 7 nm HfO₂coated Cu with NMC811 cathodes where the capacity is calculated based onthe mass of all materials including copper anodes, electrolyte andseparator. (b) Energy density and Coulombic efficiency of the cell withthe 7 nm HfO₂ coated Cu anode with the NMC811 cathode. (c) Cyclingperformance of bare Cu with NMC811 cathodes.

FIGS. 5A, 5B and 5C show the electrochemical performance of batteries ofExample 2 with HfO₂-coated Li or with bare Li, where NMC811 is used asthe cathodes. FIGS. 5A, 5B and 5C show charge-discharge performance ofbatteries with HfO₂ coated Li or with bare Li cycled at 0.33 C at roomtemperature. (a) Cycling performance of 8 nm HfO₂ coated Li with NMC811cathodes. (b) Cycling performance of bare Li with NMC811 cathodes. (c)Energy density of the battery comprising 8 nm HfO₂ coated Li with NMC811cathodes.

FIG. 6 shows voltage—energy density plots of the battery comprising 8 nmHfO₂ coated lithium from Example 2, with NMC811 cathodes in differentcycles at 0.33 C.

FIG. 7 shows a synthesis schematic for one cycle process of ALDLi_(x)HfO₂, using TDMA-Hf, H₂O and LTB as the precursors.

FIG. 8 illustrates a manufacturing process example for a spatial ALD androll-to-roll (R2R) process for making coatings on anodes and componentsaccording to the present disclosure.

FIG. 9 shows the cycling performance of coin cells of Example 3, whereinthe coin cells comprise ˜2.5 mAh/cm² sulfur as the cathode andLiF—Li₂CO₃ composite coated lithium metal or bare lithium metal as theanode.

FIG. 10 shows the cycling performance of coin cells of Example 4,wherein the coin cells comprise ˜2 mAh/cm² NMC811 as the cathode andunique ultrathin lithium metal made by Beltech or 50 microns commerciallithium metal made by mechanical press processes as the anode.

FIGS. 11A, 11B and 11C show scanning electron microscope (SEM) images ofExample 4 for the unique ultrathin lithium metal made by the presentinventor. The images show the thickness, the smoothness andcross-section of 30 microns lithium metal on copper foil.

The present teachings are best understood from the following detaileddescription when read with the accompanying drawing figures. Thefeatures are not necessarily drawn to scale. Wherever practical, likereference numerals refer to like features.

DETAILED DESCRIPTION

It is to be understood that the terminology used herein is for purposesof describing particular embodiments only, and is not intended to belimiting. The defined terms are in addition to the technical andscientific meanings of the defined terms as commonly understood andaccepted in the technical field of the present teachings. As usedherein, a “battery” refers to any container in which chemical energy isconverted into electricity and used as a source of power. The termsbattery and cell are generally interchangeable when referring to oneelectrochemical cell, although the term battery can also be used torefer to a plurality or stack of electrically interconnected cells. Abattery includes an anode and a cathode operationally connected by anelectrolyte, and typically includes various other battery componentssuch as separators, current collectors, housings.

A lithium-ion battery typically includes an anode and a cathodeseparated by an electrically insulating barrier or separator, and theelectrolyte medium typically includes one or more lithium salts and asolvent such as an organic carbonate material. During the chargingprocess, the positively charged lithium ions move from the cathode,through the permeable separator, to the anode and reduce into Li metal.During discharge, the Li metal is oxidized to positively charged lithiumions which move from the anode, through the separator, and onto thecathode, while electrons move through an external load from the anode tothe cathode, yielding current and providing power for the load. Duringthe initial charging, the surface of the anode may react with lithiumions and components of the electrolyte to form a layer of materialreferred to as a “solid electrolyte interface” (SEI) layer. As usedherein, the term “lithium battery” generally refers to lithium ionbatteries, but also encompasses lithium-sulfur batteries and otherbatteries comprising a lithium-based material.

In the present disclosure, the terms “coating” and “film” generally havethe same meaning unless the context indicates otherwise. The terms“protective” and “inert” also generally mean the same. As will beapparent from the present disclosure, an inert thin film may function asa protective coating, and a protective coating may have one or morephysical characteristics of a thin film.

As used herein, a “layer” refers to a structure having length, width andthickness, and generally the thickness is smaller than length and/orwidth. A layer generally comprises opposing major surfaces defined bythe length and width and separated from each other by the thickness.Layers can be selected to possess one or more properties, such aspermeability, conductivity, or others. For instance, layers can bepermeable, semipermeable, or substantially impermeable, whereinpermeability is determined with respect to one or more substances.Layers can be electrically conductive, semi-conductive or insulating. Athin layer is one where the thickness is much smaller than length and/orwidth, such as where the thickness is at least 10^(x) smaller the lengthand/or width, where x is −3, −4, −5, −6, −7, −8 or a lower negativenumber.

Throughout this disclosure, any of the metal layers of anodes orcathodes described herein can have a thickness of at least 200 nm, or500 nm, or 750 nm, or 1 μm, or 2 μm, or 5 μm, or 7.5 μm, or 10 μm, or 20μm, or 25 μm, or 50 μm; and/or a thickness of at most 500 μm, or 400 μm,or 300 μm, or 200 μm, or 150 μm, or 125 μm, or 100 μm, or 90 μm, or 75μm, or 60 μm. It is contemplated that any of these minimums and maximumscan be combined to form a range (e.g., a thickness from 10 to 150 μm,and that any of these values can be approximate (e.g., about 50 μm). Anyof the protective coatings, thin layers or inert layers described hereincan have a thickness of at least 0.24 nm, or 0.48 nm, or 1 nm, or 2 nm,or 5 nm, or 10 nm, or 25 nm, or 50 nm, or 100 nm, or 250 nm, or 500 nm,or 1 μm, or 5 μm; and/or a thickness of at most or 500 nm, or 1 μm, or2.5 μm, or 5 μm, or 7.5 μm, or 10 μm, or 20 μm, or 25 μm, or 50 μm. Itis contemplated that any of these minimums and maximums can be combinedto form a range (e.g., a thickness from 10 nm to 1 μm, and that any ofthese values can be approximate (e.g., about 250 nm).

In the present disclosure, various depositions techniques are employedfor creating or applying layers. For instance, a protective layer can beformed on a metal layer by chemical vapor deposition or atomic layerdeposition. In chemical vapor deposition (CVD), a substrate is exposedto one or more precursors which react on the substrate to produce thedeposited layer or film. Atomic layer deposition (ALD) is a chemicalvapor deposition where precursors are sequentially provided to reactwith a surface (such as a substrate or a previously deposited layer ofprecursor). By repeated exposure to separate precursors, a thin film isdeposited. Other deposition techniques which may be used in accordancewith the present disclosure are spatial atomic layer deposition, plasmaenhanced atomic layer deposition, plasma enhanced chemical vapordeposition, sputtering, physical vapor deposition, spinning coating, dipcoating, or pulsed laser deposition. Spatial atomic layer deposition(SALD) is based on separating the precursors in space rather than intime. With SALD, one may avoid the step of purging precursors astypically done in ALD, so faster deposition rates are achievable.“Plasma enhanced” deposition techniques employ gases that have beenpartially ionized, and high energy electrons in the plasmas can be usedto disassociate precursors or reactants into highly reactive radicals.

As one aspect of the present invention relates to the use of advancedmaterials to coat metal anodes, including lithium, sodium and potassium.These advanced materials are formed as thin films. The thin films can beapplied by thin film deposition techniques, including, but not limitedto, chemical vapor deposition, atomic layer deposition, pulsed laserdeposition, physical vapor deposition, dip coating, spin coating,electroplating, or molecular-beam epitaxy.

In some embodiments, the protective coating comprises a metal-basedcomposite where the metal is the same as in the metal layer. Theadvanced materials for lithium metal, for example, can belithium-incorporated composites, which means it is formed by two or morecompounds. In some embodiments, the composite material can be a lithiumfluoride (LiF) based composite, such as lithium fluoride-lithium oxide(LiF—Li₂O), lithium fluoride-lithium carbonate (LiF—Li₂CO₃), lithiumfluoride-lithium hexafluorophosphate (LiF—LiPF₆), lithiumfluoride-lithium phosphate (LiF—LiPO₄), lithium fluoride-lithiumtetrafluoroborate (LiF—LiBF₄), lithium fluoride-carbon fluoride(LiF—CF₄) or any combination of these materials. In some embodiments,the composite material comprises lithium fluoride-lithium oxide(LiF—Li₂O), lithium fluoride-lithium carbonate (LiF—Li₂CO₃), lithiumfluoride-lithium hexafluorophosphate (LiF—LiPF₆), lithiumfluoride-lithium phosphate (LiF—LiPO₄), lithium fluoride-lithiumtetrafluoroborate (LiF—LiBF₄), lithium fluoride-carbon fluoride(LiF—CF₄), Li₂O—Li₂CO₃, Li₂O—LiF, Li₂O—LiPO₄, Li₂O—LiBF₄, Li₂O—CF₄,HfO₂, Li_(x)HfO₂, SiO₂, LiF—NbO₂, Li₃N—AlN, Li_(x)Si₃N₄, Li_(x)Nb₃N₄,where where X≥0, or any combination of these materials. These compoundswill be combined uniformly in the composite material for the protectivecoating. In some embodiments, the protective coating or film comprises acomposite material selected from lithium oxide-contained composites,including Li₂O—Li₂CO₃, Li₂O—LiF, Li₂O—LiPO₄, Li₂O—LiBF₄, Li₂O—CF₄, orany combination of these materials. For a sodium or potassium anode, theadvanced materials are the same compositions but based on sodium orpotassium in place of lithium. For example, the composite material forsodium can be sodium fluoride-sodium oxide (NaF—Na₂O), and for apotassium anode, it can be potassium fluoride-potassium oxide (KF—K₂O).

In some embodiments, a metal anode having a protective coating comprisesa metal layer comprising lithium, sodium, or potassium; and a protectivecoating or film formed on the metal layer, wherein the film comprises acomposite material, and the composite material comprises lithiumfluoride-lithium oxide (LiF—Li₂O), lithium fluoride-lithium carbonate(LiF—Li₂CO₃), lithium fluoride-lithium hexafluorophosphate (LiF—LiPF₆),lithium fluoride-lithium phosphate (LiF—LiPO₄), lithium fluoride-lithiumtetrafluoroborate (LiF—LiBF₄), lithium fluoride-carbon fluoride(LiF—CF₄) or any combination of these materials. These compounds will becombined uniformly in the composite material for the protective coating.In some embodiments, the protective coating or film comprises acomposite material selected from (a) lithium oxide-containingcomposites, including Li₂O—Li₂CO₃, Li₂O—LiF, Li₂O—LiPO₄, Li₂O—LiBF₄,Li₂O—CF₄, or any combination of these materials when the metal layercomprises lithium; (b) sodium oxide-containing composites, includingNa₂O—Na₂CO₃, Na₂O—NaF, Na₂O—NaPO₄, Na₂O—NaBF₄, Na₂O—CF₄, or anycombination of these materials when the metal layer comprises sodium,and (c) potassium oxide-containing composites, including K₂O—K₂CO₃,K₂O—KF, K₂O—KPO₄, K₂O—KBF₄, K₂O—CF₄, or any combination of thesematerials when the metal layer comprises potassium.

In some embodiments, a metal layer of the metal anode has a thickness of10-100 μm, alternatively 1-200 μm, alternatively 1-300 μm, wherein themetal (M) is lithium, sodium or potassium.

In some embodiments, the protective coating is a protective layer formedor coated on the metal layer, wherein the protective layer has athickness from 1 nm to 10 microns. The protective coating can be formedon the metal layer, such as by being deposited on one or both majorsurfaces of the metal layer, and in some embodiments, one or both majorsurfaces of a metal layer are entirely covered by a protective coating.In some embodiments, the protective layer comprises HfO₂, M_(x)HfO₂,SiO₂, MF-M₂O, MW-M₂CO₃, MF-MPF₆, MF-M₃PO₄, MF-MBF₄, MF-CF₄, MF-NbO₂,M₂O-M₂CO₃, M₂O-MF, M₂O-M₃PO₄, M₂O-MBF₄, M₂O—CF₄, M₃N—AlN, M₃N—AlN,M_(x)Si₃N₄, M_(x)Nb₃N₄, or any combination thereof, where X≥1 and M isLi, Na, K, or a mixture thereof.

For example, the metal anode can comprise ultrathin lithium (e.g., 20micrometer) as the metal layer and an ion-conductive, conformal coatingas the protective coating on the ultrathin lithium layer. The coatingcan be prepared using atomic layer deposition or spatial atomic layerdeposition (SALD) or other thin film deposition technique. In someembodiments, the protective coating comprises two or more layers, suchas a layer of hafnium oxide (HfO₂) and a layer of lithiated hafniumoxide (Li_(x)HfO₂), thereby providing a highly Li⁺ conductive, theultrastable ability as well as high electronic resistant film for theultrathin lithium metal layer. HfO₂ possesses a shear modulus as high as130 GPa. Through incorporation of lithium and the coating optimization(Li composition and film thickness), a suitable metal anode can be madefor inclusion in Li-ion batteries such as coin cells and pouches havingNMC as the cathode.

In view of the relatively low ionic conductivity of HfO₂, it isdesirable to include lithium into the HfO₂ to form a film comprisingLi_(x)HfO₂, where X≥0. Such a film has great Li⁺ conductivity and can bedeposited directly onto lithium metal foils through ALD or SALD. Withthis higher ion-conductive coating, the cycle life will be greatlyextended because Li_(x)HfO₂ can readily facilitate the lithium ionstransportation and enable uniform lithium stripping/plating process. Thecurrent rate for charge and discharge of the battery systems using thepresent anode materials can be higher than 0.33 C and provide higherpower devices for different applications, such as drones and vehicles.It is contemplated that a combination of lithium and HfO₂ in a thinlayer can dramatically increase the lithium-ion conductivity to 10⁻⁴S/cm scale (Huang, B., et al., “Li-ion conduction and stability ofperovskite Li_(3/8)Sr_(7/16)Hf_(1/4)Ta_(3/4)O₃.” 2016. 8(23): p.14552-14557), and it possesses great mechanical strength, up to 130 GPa,which is about 15 times the sufficient value (8.5 GPa) to prevent thelithium dendrites, as well as high chemical stability in a wideelectrochemical window.

A schematic diagram for Li_(x)HfO₂ is shown in Figure C. The precursorsto synthesize HfO₂ by atomic layer deposition aretetrakis(dimethylamido) hafnium (TMDA-hafnium) and water. The waterhoused in a room-temperature container reacts with the fourdimethylamino ligands and forms oxide, bonding to the Hf element. Thereaction can be cycled for N times and the growth rate is 1 angstrom (Å)per cycle, so that from the reaction the thickness of HfO₂ is N Å. Theincorporation of lithium into the HfO₂ thin film is completed bypreparing Li₂O. The precursors to synthesis the Li₂O film by ALD arelithium tert-butoxide (LTB) and water. LTB is contained and heated at135° C. with argon as the carrier gas, and carried into the ALD reactor.The three methyl groups react well with water and form oxides, bondingto the lithium element. This reaction also can be cycled for M times andthe growth rate is 1.2 Å/cycle, so that the thickness of Li₂O is 1.2M Å.For the final coating, i.e., M(Li₂O)·N(HfO₂), the composition andthickness depend on the number of M and N, where M is ≥0 and N is ≥1. Tosimplify the description of this material, it is sometimes referred toas Li_(x)HfO₂ herein.

The present metal anodes can also comprise a current collector, such ascopper and stainless steel. For example, a metal layer may have firstand second major surfaces, and a protective coating may be disposed onthe first major surface and the current collector may be disposed on thesecond major surface.

In some embodiments, the protective coating or one or more layers of thecoating comprises MF-M₂CO₃, MF-M₃N, HfO₂, M_(x)HfO₂ (metal-ionintegrated HfO₂), or any combination thereof. The protective layer canbe formed on the metal layer by atomic layer deposition, plasma enhancedatomic layer deposition, chemical vapor deposition, plasma enhancedchemical vapor deposition, sputtering, physical vapor deposition,spinning coating, dip coating, or pulsed laser deposition.

The metal anodes having a protective coating as described herein can beused to solve several problems, such as the formation of dendritesthough not every embodiment necessarily solves every problem. Metalanodes form dendrites that can penetrate the battery separator andreaches the cathode side to cause short circuits during charge anddischarge processes. Putting a protective coating or thin film on themetal anode will suppress the lithium dendrite and solve the problem.The inorganic composite film has excellent mechanical properties thatcan suppress dendrite formation on metal anodes, and has great ionicconductivity, leading to high charge-discharge rate with stableelectrode morphology. Thus, the short circuit is prevented and thebattery using metal anodes will be safe.

The present metal anodes can also solve the problem of electrolyteconsumption. Liquid electrolyte or solid electrolyte will be reducedwhen contacted with metal anodes. Such thin film coating on metal anodescan prevent or largely diminish the electrolyte consumption because thefilm prevents the direct contact between metal anodes and electrolyte.Longer Use Life: Coupled with either of solid electrolyte or liquidelectrolyte, protected metal anodes cannot contact the electrolytedirectly with the protection layer between them. Thus, it largelydiminishes the electrolyte consumption. Also, with less dendrites, thesurface area of metal anodes is decreased and the contact area betweenthe anode and the electrolyte is reduced for less electrolyteconsumption as well. The batteries with protected metal anodes consumingless electrolyte will last longer.

The present metal anodes can overcome one or more of the problemsassociated with by providing coatings to act as artificial SEI layers.In order to achieve homogenous current distributions for ultrastablelithium anodes in a cell, it is desirable that an SEI meets severalcriteria:

-   -   1) chemically stable in a highly reducing environment;    -   2) compositionally homogenous and conformal to house lithium        beneath the SEI;    -   3) intimate contact or strong adhesion with lithium metal for        minimized resistance and accommodating the volume changes;    -   4) electronic insulating or possess large nucleation energy for        lithium for uniform current distribution;    -   5) high shear modulus to greatly suppress lithium dendrites.        Besides, the coating with high lithium ionic conductivity can        facilitate the ion transportation and lead to uniform lithium        stripping and platting.

The present metal anodes can be incorporated into and configured for usein Li-ion batteries, such as coin cells and pouch cells, such asbatteries comprising lithium nickel manganese cobalt oxide (NMC) as thecathode (for example, 34×50 mm² pouch cells with double-sides coated 5mAh/cm² NMC cathodes). In some embodiments, the present disclosureprovides batteries having: (a) a battery energy density of 450 Wh/kg orhigher (cell level) and/or 400 Wh/kg or higher (battery level); (b)battery cycle life, measured by retention of 80% of its initialcapacity, of 250 cycles or higher, alternatively 1,000 cycles or higher;(c) wide temperature operations including the range of −20° C. to 55° C.

The present metal anodes can be incorporated into and configured for usein drones, consumer electronics, automotive, grid and defense. Any otherareas that need power sources, our technology can find an application.

As another aspect, the present disclosure provides coatings and filmscomprising hafnium oxide (HfO₂) or lithium hafnium oxide (Li_(x)HfO₂,where X≥0), as well as novel methods of making such coatings and films.In some embodiments, the protective coating is formed on an electrode(an anode or a cathode) configured for use in a lithium ion battery,such as to permit intercalation of lithium ions. Hafnium oxide has beenused in the semiconductor industry, but it is not known as being used asan anode coating. Hafnium oxide has excellent performance as anartificial SEI. It is very stable in contact with lithium metal and hasexcellent stability at a wide electrochemical window. With regard to thehigh dielectric constant, the k value of HfO₂ is as high as 25, comparedto the k=8 of Al₂O₃ that was used for lithium metal protection in theliterature. Studies have shown that materials with shear modulus of 8GPa are able to suppress lithium dendrites (Yu, S., et al., “Elasticproperties of the solid electrolyte Li₇La₃Zr₂O₁₂ (LLZO).” 2015. 28(1):p. 197-206.), while HfO₂ possesses a shear modulus as high as 130 GPa,over 15 times that of the desired shear modulus.

Conventional methods of applying certain thin films require hightemperature (>400° C.) that would melt lithium (melting point: 181° C.)for the HfO₂ synthesis. Besides, only the atomic layer deposition (ALD)technology can make conformal and pure HfO₂ films, excluding methodslike physical vapor deposition (PVD), at very low temperature (150° C.).

Preferably, the protective layer is formed by atomic layer deposition orplasma enhanced atomic layer deposition.

In some embodiments, the metal of the metal layer is Li and theprotective layer is Li_(x)HfO₂ where x≥0.

As another aspect, the present disclosure provides coatings and filmscomprising lithium fluoride (LiF) based composite coating, such aslithium fluoride-lithium carbonate (LiF—Li₂CO₃), as well as novelmethods of making such coatings and films. In some embodiments, theprotective coating on an anode or cathode comprises lithiumfluoride-lithium carbonate. LiF and Li₂CO₃ has excellent performance asan artificial SEI. It is very stable in contact with lithium metal andhas excellent stability at a wide electrochemical window. Studies haveshown that materials with shear modulus of 8 GPa are able to suppresslithium dendrites (Yu, S., et al., “Elastic properties of the solidelectrolyte Li₇La₃Zr₂O₁₂ (LLZO).” 2015. 28(1): p. 197-206.), whileLiF—Li₂CO₃ possesses a shear modulus as high as 50-120 GPa, severaltimes that of the desired shear modulus. LiF—Li₂CO₃ possesses high ionconductivity that can accommodate the fast lithium ion stripping andplating.

Conventional methods of applying certain thin films require hightemperature (>200° C.) that would melt lithium (melting point: 181° C.)for the LiF and Li₂CO₃ synthesis. The atomic layer deposition (ALD)technology can make conformal and pure LiF—Li₂CO₃ films, and methodslike physical vapor deposition (PVD) can make the pure compositecoating, at very low temperature (150° C.).

Preferably, the protective layer is formed by atomic layer deposition orplasma enhanced atomic layer deposition. In some embodiments, the metalof the metal layer is Li and the protective layer is LiF—(Li₂CO₃)_(x)where x≥0.

As another aspect of the present invention, novel cathodes and batterycomponents are provided. The cathodes comprise a thin film or layer onan aluminum metal layer, such as a lithium-based material. In someembodiments, the cathodes comprise a metal oxide or sulfur-basedmaterial having a surface, and an inert material coating the surface ofthe metal oxide or sulfur-based material layer. In other embodiments,other battery components comprise the protective coating on a batterycomponent layer or material.

The cathodes comprise a high voltage and energy, lithium-based materialhaving a surface layer material comprising a thin layer comprising aninert material. The cathodes are configured for use as the cathode of alithium-ion battery. In some embodiments, the cathodes comprise a highenergy, sulfur-based material having a surface layer material comprisinga thin layer and an inert material. The cathodes are configured for useas the cathode of lithium-sulfur battery.

In some embodiments, the inert material comprises a metal, a metaloxide, a metal halide, a metal oxyfluoride, a metal nitride, a metalcarbonate, a metal sulfide, a metal sulfate, a metal phosphate, anon-metal oxide, a non-metal carbide, a non-metal, or mixture of any twoor more thereof. In some embodiments, the inert material comprises amaterial selected from the group consisting of Al, Cu, Al₂O₃, TiO₂, ZnO,La₂O₃, NbO₂, ZrO₂, Li₂O, HfO₂, GaO₂, GeO₂, CeO₂, MgO, CaO, LiF, AlF₃,LiAlF₄, MgF₂, Zn₂OF₂, Li₃FO, LiCF₅, Li₃N, TiN, Li₂CO₃, CaCO₃, ZnCO₃,La₂(CO₃)₃, Nb (CO₃)₂, MgCO₃, Li₂S, ZnS, GaS₂, TiS₂, NbS₂, HfS₂, CaS,La₂S₃, BaSO₄, Li₃PO₄, AlPO₄, WF₄, W(PO₄)₂, SiO₂, SiC, Si, carbon, ormixtures of any two or more thereof. In some embodiments, the inertmaterial comprises a hafnium oxide, lithium hafnium oxide, a lithiumfluoride-lithium carbonate composite, LiF, La₂O₃, NbO₂, ZrO₂, Li₂O,GaO₂, GeO₂, CeO₂, MgO, CaO, AlF₃, LiAlF₄, MgF₂, Zn₂OF₂, Li₃FO, LiCF₅,Li₃N, TiN, Li₂CO₃, CaCO₃, ZnCO₃, La₂(CO₃)₃, Nb (CO₃)₂, MgCO₃, Li₂S, ZnS,GaS₂, TiS₂, NbS₂, HfS₂, CaS, La₂S₃, BaSO₄, Li₃PO₄, AlPO₄, WF₄, W(PO₄)₂,lithium niobium oxides, lithium hafnium oxides and lithium lanthanumoxides, lithium oxide (Li₂O), lithium phosphate (Li₃PO₄), lithiumsilicon oxide, lithium aluminum phosphate (Li_(x)AlPO₄), and lithiumfluoride containing composite materials, or mixtures of any two or morethereof.

The cathodes comprise a metal layer with any cathode material. In someembodiments, the metal layer comprises a cathode material such as alithium-based cathode material. In some examples, cathode material isLi_(X)Ni_(Y)Mn_(Z)Co_(N)O₂ (NMC, X≥1, Y≥0.6, Z≥0.1, N≥0),Li_(X)Ni_(Y)Mn_(N)O₂ (NMO, X≥1, Y≥0.2, N≥0.2), orLi_(X)Ni_(Y)Co_(Z)Al_(N)O₂ (NCA, X≥1, Y≥0.6, Z≥0, N≥0.01), where someother metals, such as aluminum, titanium or manganese, might be doped inthe material with ratio of less than 0.015.

In some embodiments, the cathode material is selected fromLi_(X)Ni_(Y)Mn_(Z)Co_(N)O₂ (NMC, X≥1, Y≥0.6, Z≥0.1, N≥0),Li_(X)Ni_(Y)Mn_(N)O₂ (NMO, X≥1, Y≥0.2, N≥0.2), andLi_(X)Ni_(Y)Co_(Z)Al_(N)O₂ (NCA, X≥1, Y≥0.6, Z≥0, N≥0.01), optionallywith a dopant. The dopant can be another metals, such as aluminum,titanium or manganese, and it might be doped in the cathode materialwith ratio of less than 0.02, or 0.015, or 0.01. Cathode layers can besynthesized from cathode materials in powder form (or other form) byflame-assisted pyrolysis, preferably with powder size from 50 nm to 50μm.

In some embodiments, the present cathodes comprise a lithium-basedmaterial having a surface; and a thin layer comprising an inert materialon the surface.

As other embodiments, the battery component having a thin film or aprotective coating is a membrane/separator. Instead of a cathode layeror cathode material, the component comprises membrane/separatormaterials.

The present cathodes and battery components comprise a thin layer on thecathode material, membrane/separator material, or other componentmaterial. The thin layer can have a thickness of 0.1 nm to 10 microns,wherein the thin layer comprises an inert material, such as HfO₂,M_(x)HfO₂, SiO₂, MF-M₂O, MF-M₂CO₃, MF-MPF₆, MF-M₃PO₄, MF-MBF₄, MF-CF₄,MF-NbO₂, M₂O-M₂CO₃, M₂O-MF, M₂O-M₃PO₄, M₂O-MBF₄, M₂O—CF₄, M₃N—AlN,Li₃N—AlN, Li_(x)Si₃N₄, Li_(x)Nb₃N₄, or any combination thereof, whereinM can be lithium or sodium or magnesium or any combination thereof and xcan be >0. In some embodiments, the thin layer comprises MF-M₂CO₃,MF-M₃N, HfO₂, M_(x)HfO₂ (metal-ion integrated HfO₂), or any combinationthereof.

In some embodiments, the cathode material can be nanosized or microsizedpowder, and/or the cathode material can be sulfur or lithium sulfidepowders, and/or the thin layer can comprise two or more layers of theinert material.

As another aspect, a process for preparing a cathode is provided. Theprocess comprises depositing a thin layer of inert material onto a layerof cathode material by dip coating, sputter coating, chemical vapordeposition, atomic layer deposition, or spin coating on the surface of acathode material as powders or a cathode laminate, wherein the powderscan be made by any approach, including sol-gel method, solid statereactions, ultrasonic spray pyrolysis, flame-assisted pyrolysis,liquid-feed flame spray pyrolysis, or co-precipitation. The cathode isconfigured for use as a cathode in a lithium-ion battery.

In some embodiments, the thin layer is formed by atomic layerdeposition, plasma enhanced atomic layer deposition, chemical vapordeposition, plasma enhanced chemical vapor deposition, sputtering,physical vapor deposition, spinning coating, dip coating, or pulsedlaser deposition. Preferably, the protective layer is formed by atomiclayer deposition or plasma enhanced atomic layer deposition.

In some embodiments of the present cathode or process, the cathodematerial is made with average diameter of 50 nm to 50 μm powders and/orthe cathode material is mixed with a binder and conductive additives fora cathode as a laminate. For example, the process can comprise formingthe metal layer from a cathode material powder, which has a suitableparticle size, such as a mean particle size from 50 nm to 50 μm, or from500 nm to 5 μm.

In some embodiments, the depositing of the thin layer comprisesdepositing the thin layer in one or more multiple times or cycles;and/or the depositing of the thin layer is by atomic layer deposition orchemical vapor deposition. For instance, depositing of the thin layercan comprise providing an inert material precursor configured todecompose or react in the depositing to form the inert material. In someembodiments, the inert material precursor is a trimethylaluminum, AlCl₃,tris-(dimethylamido)aluminum, trialkylaluminum, trifluoroaluminum,trichloroaluminum, tribromoaluminum, AlMe₂Cl, AlMe₂OPr, Al(OEt)₃,Al(OPr)₃, ZrCl₃, ZrCl₄, ZrI₄, ZrCp₂Cl₂, ZrCp₂Me₂, Zirconiumtert-butoxide or called Zr(OtBu)₄, Zr(dmae)₄, Zr(thd)₄, Zr(NMe₂)₄,Zr(NEt₂)₄, Zr(OPr)₂(dmae)₂, Zr(OtBu)₂(dmae)₂, Zr(NEtMe)₄, ZnCl₂, ZnEt₂,ZnMe₂, Zn(OAc)₂, SiCl₄, SiCl₃H, SiCl₂H₂, Bis(trimethylsilyl)amine,Si(NCO)₄, MeOSi(NCO)₃, GeCl₄, MgCp₂, Mg(thd)₂, TiCl₄, TiI₄, Ti(OMe)₄,Ti(OEt)₄, Ti(OPr)₄, Ti(OPr)₂(dmae)₂, Ti(OBu)₄, or Ti(NMe₂)₄,tris(iso-propylcyclopentadienyl) lanthanum, La(TMHD)₃, TDMASn, TDMAHf,HfCl₄, LiOtBu, CO₂, water, oxygen, ozone, hydrogen fluoride, hydrogenfluoride pyridine, tungsten hexafluoride,(tert-butylimido)-tris(diethylamino)-niobium or called tBuN=Nb(NEt₂)₃,tBuN=Nb(NMeEt)₃, H₂S, bis-(tri-Isopropylcyclopentadienyl)calcium,disilane (Si₂H₆), silane (SiH₄), monochlorosilane (SiH₃Cl), C₂H₂, CCl₄,CHCl₃, and mixtures thereof.

The inert material precursors can be manipulated to tune the elementratio in the material. The inert material precursors can be metalorganics which permit the material synthesis to be performed at lowtemperatures (e.g., from 80° C. to 300° C.). The synthesized materialcan then be sintered at high temperature if desired.

In some embodiments, the inert material precursors are inorganics andthus the material synthesis is performed at high temperature (e.g., 500°C.-1200° C.).

In some embodiments, a chemical vapor based technology, such as atomiclayer deposition and chemical vapor deposition, to make a thin film orprotective coating on cathode material powders onto cathode laminatesafter casting of cathode material powders onto current collectors. Thepresent process can also comprise forming the metal layer by mixing thecathode material with a binder and conductive additives to form alaminate. For example, the cathode material, the binder, and theconductive additivies can be cast onto a current collector beforeforming the laminate.

In some embodiments, the thin film or coating can be deposited ontosulfur-based cathodes, such as lithium sulfide (Li₂S). Suitable coatingor inert materials can be lithium metal oxides (lithium niobium oxides,lithium hafnium oxides and lithium lanthanum oxides, etc.), lithiumoxide (Li₂O), lithium phosphate (Li₃PO₄), lithium silicon oxide, lithiumaluminum phosphate (Li_(x)AlPO₄), and lithium fluoride based materials,including but not limited to LiF, and lithium fluoride based compositionmaterials such as lithium aluminum fluoride (Li_(x)AlF_(y)), lithiumtungsten aluminum fluoride (Li_(x)WAlF_(y)), lithium fluoride-lithiumoxide (LiF—Li₂O), lithium fluoride-lithium carbonate (LiF—Li₂CO₃),lithium fluoride-lithium hexafluorophosphate (LiF—LiPF₆), lithiumfluoride-lithium phosphate (LiF—LiPO₄), lithium fluoride-lithiumtetrafluoroborate (LiF—LiBF₄) and lithium fluoride-carbon fluoride(LiF—CF₄), or any combination of these materials.

The present disclosure also relates to a novel method of preparinglithium-free anodes, capable of making safe, high energy, and low-costlithium ion batteries.

In one aspect, the present disclosure provides a method of preparinglithium-metal free anodes and coated metal foils as the anode materialsof lithium-ion batteries or starting materials for such anodes. Themethod may include: atomic layer deposition (ALD), chemical vapordeposition (CVD), plasma enhanced chemical vapor deposition (PECVD),sputtering, physical vapor deposition (PVD), plasma enhanced atomiclayer deposition (PEALD), spinning coating, dip coating, pulsed laserdeposition (PLD), or any combination thereof.

In some embodiments, the method of preparing an anode configured for usein a lithium-ion battery comprises depositing a coating material on ametal substrate by atomic layer deposition (ALD), chemical vapordeposition (CVD), plasma enhanced chemical vapor deposition (PECVD),sputtering, physical vapor deposition (PVD), plasma enhanced atomiclayer deposition (PEALD), spinning coating, dip coating, pulsed laserdeposition (PLD), or any combination thereof, wherein the coatingmaterial is dielectric and lithium-ion conductive. The presentdisclosure relates to the metal substrate materials coated with advancedmaterials made by the deposition technologies listed above. The metalsubstrate includes, but is not limited, to copper, nickel, titanium,carbon or graphite foil, tantalum (Ta) foil, tungsten (W) foil, vanadium(V) foil, or stainless steel or any combination thereof. The thicknessof the substrate can range from 0.1 microns to 50 microns.

In yet another aspect, the present disclosure provides coating materialsmade by the deposition technologies listed above onto the metalsubstrate. The coating materials are dielectric, which means that theyare good electronic barrier materials. Also, they may possess goodlithium-ion conductive property. The materials include, but are notlimited to, aluminum oxide, titanium oxide, hafnium oxide, zirconiumdioxide, lithium oxide, lanthanum oxide, zinc oxide, antimony tetroxide,antimony pentoxide, arsenic trioxide, arsenic pentoxide, barium oxide,bismuth oxide, bismuth oxide, calcium oxide, cerium oxide, cerium oxide,chromium oxide, chromium oxide, chromium oxide, chromium oxide, cobaltoxide, cobalt oxide, cobalt oxide, copper oxide, copper oxide, ironoxide, iron oxide, lead oxide, magnesium oxide, manganese oxide, mercuryoxide, nickel oxide, rubidium oxide, silicon dioxide, silver oxide,thallium oxide, thallium oxide, thorium oxide, tin oxide, uranium oxide,tungsten oxide, selenium dioxide, tellurium dioxide, lithium sulfide,lithium nitride, lithium nitrate, lithium carbonate, lithium fluoride,lithium chloride, lithium bromide, lithium carbide, lithium borate,lithium sulfate, lithium hexafluorophosphate, lithium hydroxide, lithiumtantalite, lithium iodide, lithium tetrakispentafluorophenyl borate,yttrium lithium fluoride, polyethylene glycol, gelatin, orpolytetrafluoroethylene, or any combination thereof. The thickness ofthe coating can range from 0.1 nanometers to 50 microns. In someembodiments, the thickness can range from 0.5 nm to 500 nm.

In one example, the present disclosure provides a method of preparingadvanced dielectric materials coated metal foils. The coated metal foilscan be used as the anode of lithium-ion batteries, wherein the methodcomprises: employing (that is, providing or obtaining) metal foils suchas commercial metal foils, including copper, stainless steel and nickelfoils, optionally with a treatment, such as cleaning of the foils byacids and organics to remove oxide and organics residues, respectively.The method also comprises applying the coating materials described aboveusing film deposition methods, such as CVD, PECVD, ALD, sputtering, PVD,PEALD, spinning coating, dip coating, PLD, to make a coating onto themetal foils, such as Cu, Ni or stainless steel. The coating material isdielectric, and can be selected from the coating materials disclosedherein.

In some embodiments, the coating thickness can range from 0.1 nanometersto 50 microns, preferably from 0.5 nm to 500 nm. The metal foilthickness can range from 0.1 μm to 50 μm.

In another example, the present disclosure provides a method ofpreparing advanced dielectric materials with high Li-ion conductivitycoated metal foils as the anode of lithium-ion batteries, wherein themethod comprises: employing metal foils such as commercial metal foils,including copper, stainless steel and nickel foils, optionally with atreatment, such as cleaning of the foils by acids and organics to removeoxide and organics residues, respectively; and using the technicalmethods, such as CVD, PECVD, ALD, sputtering, PVD, PEALD, spinningcoating, dip coating, PLD, to make a coating onto the metal foils, suchas Cu, Ni or stainless steel.

The coating material is dielectric and has high lithium-ionconductivity. The coating material can comprise a lithium-incorporatedcompound, including but not limited to lithium phosphorus oxynitride(LiPON), Li₃YCl₆, Li₃YBr₆, Li₉S₃N, Li_(1+x)Al_(x)Ge_(y)Ti_(2−x−y)(PO₄)₃(0≤x≤0.8; y=0.8, 1.0), Li₇La₃Zr₂O₁₂, Al-doped Li₇La₃Zr₂O₁₂,Li(NH₃)_(n)BH₄ (0<n≤2), LiCoO₂, LiMn₂O₄, LiFePO₄, Li₁₄ZnGe₄O₁₆, lithiumlanthanum titanate, Li₁₀GeP₂S₁₂, Li_(1+x)Ge_(2−y)Al_(y)P₃O₁₂, Li₈S₉P₂,Li₃FCO₃ or any combination thereof.

The coating thickness can range from 0.1 nanometers to 50 microns,preferably from 0.5 nm to 500 nm. The metal foil thickness can rangefrom 0.1 μm to 50 μm.

In some embodiments of the present disclosure, the prepared coating issubstantially homogeneous and uniform in compositions and thickness.

As another aspect, method of preparing a thin layer comprising lithiumare provided. The thin layer can be used as a metal anode in a lithiumbattery, or may be a part of an anode. The method comprises: a) applyingone or more interlayer material onto a substrate to form an interlayermaterial coated substrate. The interlayer material can comprise a metalsuch as aluminum metal, tin metal, indium metal, zinc metal, nickelmetal, molybdenum metal and titanium metal, or any metal oxide or metalnitride, such as Al₂O₃, CuO, ZnO, TiO₂, HfO₂, aluminum nitride (AlN),Li₂O, SiO₂, NbO₂, Fe₂O₃, Fe₃O₄, FeO, MnO₂, Li₃N, Li₂CO₃, Si₃N₄ andNb₃N₄, or any organic materials such as carbonates and ester, orsilicon, or any combination thereof. The substrate can comprise copper(Cu) foil, nickel (Ni) foil, stainless steel foil, titanium (Ti) foil,carbon or graphite clothing, tantalum (Ta) foil, tungsten (W) foil,vanadium (V) foil, or a polymer film. In some embodiments, the totalthickness of the interlayer material layer is 0.1 nm-50 μm, wherein thesubstrate has a thickness of 1.0-45 μm. The method also comprises b)applying heat to the interlayer material coated substrate to an elevatedtemperature, for example 200 celsius (° C.), or between 100 and 250° C.,or from 150 to 225° C.; and c) applying one or more metal layer onto theinterlayer material coated substrate. The metal can be lithium and canbe integrated onto the interlayer. In some embodiments, the totalthickness of the metal layer is 10 nm-100 nm.

Suitable processes of applying the one or more metal layer onto theinterlayer material coated substrate include but are not limited topressing, rolling, printing and extruding.

The interlayer material can be applied by a method comprising chemicalvapor deposition, plasma enhanced chemical vapor deposition, sputtering,physical vapor deposition, atomic layer deposition, plasma enhancedatomic layer deposition, spinning coating, dip coating, pulsed laserdeposition, or any combination thereof. In some embodiments, theinterlayer material layer is applied by physical vapor deposition oratomic layer deposition.

In some aspects, the present methods are used to form an ultrathin layerof lithium, and the metal layer can be peeled off from the substrate toprovide substrate free metal film.

In some embodiments, the interlayer material comprises aluminum metal,and the interlayer material has a thickness of 20 nm to several microns.In some embodiments, the substrate comprises a copper foil with athickness of 5-20 μm, alternatively 1-20 μm, and/or the metal layercomprises a lithium layer with a thickness of 1-50 μm.

In some embodiments, the metal coated substrate is prepared withoutbeing under vacuum, for example, at atmospheric conditions. The presentdisclosure provides an anode comprising a lithium metal based materialhaving a surface layer material comprising: a thin layer comprising aninterlayer material; wherein: the anode is configured for use as theanode of a lithium-ion battery or lithium-sulfur battery.

The present methods provide great adhesion between lithium and currentcollectors, and high lithium density with good edge are accomplished.The lithium manufacturing process can be achieved by roll-to-rollprocess or extrude printing or 3D printing with integration of thephysical or chemical vapor technology. Also, some coating materials bythe chemical vapor technology as the interlayer onto the currentcollectors can be used to protect the thin lithium metal, includinglithium metal oxides (lithium niobium oxides, lithium hafnium oxides andlithium lanthanum oxides, etc.), or the combination of two or three ofthese metal oxides.

In some embodiments, the lithium thickness in the metal layer of theanode or the ultrathin lithium layer ranges from 10 m to 100 m, and/orthe anode material is a thin lithium metal that is either formed oncurrent collectors, including copper and nickel, or free-standinglithium. In some embodiments, when there is a substrate, the substrateand the lithium metal are surface treated by chemical vapor or physicalvapor to manipulate the surface so that they are able to be integratedtogether with low resistance. In some embodiments, the lithium and thesubstrate are integrated with a roll-to-roll process.

In some embodiments, the layer material comprises a metal oxide, a metalhalide, a metal oxyfluoride, a metal nitride, a metal carbonate, a metalsulfide, a metal sulfate, a metal phosphate, a non-metal oxide, anon-metal carbide, a carbon material, or a mixture of any two or morethereof. For example, the layer material can comprise Li₂O, La₂O₃, NbO₂,ZrO₂, HfO₂, GaO₂, GeO₂, CeO₂, MgO, CaO, Li₃OF, LiF, AlF₃, MgF₂, Zn₂OF₂,Li₃FO, LiCF₅, Li₃N, TiN, Li₂CO₃, CaCO₃, ZnCO₃, La₂(CO₃)₃, Nb (CO₃)₂,MgCO₃, Li₂S, ZnS, GaS₂, TiS₂, NbS₂, HfS₂, CaS, La₂S₃, BaSO₄, Li₃PO₄,AlPO₄, WF₄, W(PO₄)₂, SiC, carbon or a mixture of any two or morethereof.

The thin layer of the anode may comprise two or more layers of the inertmaterial, and the thin layer may be deposited in one or multiple timesor cycles. The thin layer can be deposited by atomic layer deposition orchemical vapor deposition.

The depositing of the thin layer can comprise providing an inertmaterial precursor configured to decompose or react in the depositing toform the inert material. By way of example, the inert material precursorcan be selected from trimethylaluminum, AlCl₃,tris-(dimethylamido)aluminum, trialkylaluminum, trifluoroaluminum,trichloroaluminum, tribromoaluminum, AlMe₂Cl, AlMe₂OPr, Al(OEt)₃,Al(OPr)₃, ZrCl₃, ZrCl₄, ZrI₄, ZrCp₂Cl₂, ZrCp₂Me₂, Zirconiumtert-butoxide or called Zr(OtBu)₄, Zr(dmae)₄, Zr(thd)₄, Zr(NMe₂)₄,Zr(NEt₂)₄, Zr(OPr)₂(dmae)₂, Zr(OtBu)₂(dmae)₂, Zr(NEtMe)₄, ZnCl₂, ZnEt₂,ZnMe₂, Zn(OAc)₂, SiCl₄, SiCl₃H, SiCl₂H₂, Bis(trimethylsilyl)amine,Si(NCO)₄, MeOSi(NCO)₃, GeCl₄, MgCp₂, Mg(thd)₂, TiCl₄, TiI₄, Ti(OMe)₄,Ti(OEt)₄, Ti(OPr)₄, Ti(OPr)₂(dmae)₂, Ti(OBu)₄, or Ti(NMe₂)₄,tris(iso-propylcyclopentadienyl) lanthanum, La(TMHD)₃, TDMASn, TDMAHf,HfCl₄, LiOtBu, CO₂, water, oxygen, ozone, hydrogen fluoride, hydrogenfluoride pyridine, tungsten hexafluoride,(tert-butylimido)-tris(diethylamino)-niobium or called tBuN=Nb(NEt₂)₃,tBuN=Nb(NMeEt)₃, H₂S, bis-(tri-Isopropylcyclopentadienyl)calcium,disilane (Si₂H₆), silane (SiH₄), monochlorosilane (SiH₃Cl), C₂H₂, CCl₄,or CHCl₃. The inert material precursors can be manipulated or otherwiseselected to tune the element ratio in the material. In some embodiments,the inert material precursors are metal organics and the materialsynthesis can be realized at low temperature (30° C. to 160° C.).

For the present anode, the anode material can be thin lithium metal. Thelithium metal can be formed on current collectors, such as copper. Byspecial treatments on lithium metal or the current collector using thechemical vapor technology, lithium and the current collectors can beintegrated together, and the lithium metal is formed with a thicknessfrom 1 μm to 200 m. The lithium manufacturing process can be achieved byroll-to-roll process with integration of the chemical vapor technology.Also, some coating materials by the chemical vapor technology are usedto protect the thin lithium metal, including lithium metal oxides(lithium niobium oxides, lithium hafnium oxides, lithium lanthanumoxides, and others), or the combination of two, three, or more of thesemetal oxides.

As noted above, spatial atomic layer deposition (SALD) is based onseparating the precursors in space rather than in time. This can improvethe efficiency of ALD precursor dosing and pump usage so as to reducethe cost and maintenance of applying the thin layers. With thiscontinuous and efficient roll-to-roll process contemplated herein, fastproduction (>5 meters/min) can be accomplished for large scaleproduction, and the cost of material production can be decreasedsignificantly to achieve the cost of final battery products atrelatively low cost.

The present methods can be used to prepare a coated lithium layer,suitable for use as a metal anode in a lithium battery or for other useswhere an ultrathin lithium is desired. The method comprises depositing acoating material on a lithium layer by a roll-to-roll process, extrudeprinting, 3D printing or any other depositing technique. The depositingcan comprise spatial atomic layer deposition (SALD) in a roll-to-rollprocess. By way of example, the roll-to-roll process can compriseunspooling the lithium layer from a first roll, passing the lithiumlayer through a plurality of deposition zones, and spooling the coatedlithium layer on a second roll. FIG. 7 illustrates an exemplary spatialALD and roll-to-roll (R2R) process for making the metal anodes and metalcathodes described herein with high efficiency and reduced cost comparedto conventional ALD processes. The plurality of deposition zone cancomprise at least a first deposition zone comprising a first coatingmaterial precursor that reacts or decomposes on the lithium layer, and asecond deposition zone comprising a second coating material precursorthat reacts or decomposes on the first coating material precursor. Forexample, the first coating material precursor can betetrakis(dimethylamido)hafnium and the second coating material precursorcan be water. In some embodiments, the coating material comprises ametal oxide, a metal halide, a metal oxyfluoride, a metal nitride, ametal carbonate, a metal sulfide, a metal sulfate, a metal phosphate, anon-metal oxide, a non-metal carbide, a carbon material, or a mixture ofany two or more thereof. More particularly, the coating material cancomprise Li₂O, La₂O₃, NbO₂, ZrO₂, HfO₂, GaO₂, GeO₂, CeO₂, MgO, CaO,Li₃OF, LiF, AlF₃, MgF₂, Zn₂OF₂, Li₃FO, LiCF₅, Li₃N, TiN, Li₂CO₃, CaCO₃,ZnCO₃, La₂(CO₃)₃, Nb (CO₃)₂, MgCO₃, Li₂S, ZnS, GaS₂, TiS₂, NbS₂, HfS₂,CaS, La₂S₃, BaSO₄, Li₃PO₄, AlPO₄, WF₄, W(PO₄)₂, SiC, carbon or a mixtureof any two or more thereof.

The metal anodes, cathodes, and other components described herein can beincorporated into batteries or other electrochemical cells. For example,the metal anodes, cathodes, and other components can be assembled intovarious battery designs such as cylindrical batteries, prismatic shapedbatteries, coin cell batteries, or other battery shapes. The batteriescan comprise a single pair of electrodes or a plurality of pairs ofelectrodes assembled in parallel and/or series electrical connection(s).While the materials described herein can be used in batteries forprimary, or single charge use, the metal anodes, cathodes, and othercomponents generally have desirable properties for incorporation insecondary batteries (or rechargeable batteries) which are capable of useover multiple cycles of charge and discharge. The batteries can beconfigured as coin cells, pouch cells, or other cells.

The batteries and electrochemical cells described herein will compriseone or more electrolytes, which may be liquid, solid or other form.

In some embodiments, a battery comprises an electrode as describedherein, and a solid electrolyte interphase (SEI) formed by or on theprotective coating.

As used herein, and in addition to their ordinary meanings, the terms“substantial” or “substantially” mean to within acceptable limits ordegree to one having ordinary skill in the art. For example,“substantially cancelled” means that one skilled in the art considersthe cancellation to be acceptable. In the present disclosure the term“substantially” can allow for a degree of variability in a value orrange, for example, within 80%, within 85%, within 90%, within 95%, orwithin 99% of a stated value or of a stated limit of a range.

As used herein, the terms “approximately” and “about” mean to within anacceptable limit or amount to one having ordinary skill in the art. Forexample, “about 10” may indicate a range of 8.5 to 11.5. For example,“approximately the same” means that one of ordinary skill in the artconsiders the items being compared to be the same. In the presentdisclosure the term “about” can allow for a degree of variability in avalue or range, for example, within 20%, within 10%, within 5%, orwithin 1% of a stated value or of a stated limit of a range.

In the present disclosure, numeric ranges are inclusive of the numbersdefining the range. It should be recognized that chemical structures andformula may be elongated or enlarged for illustrative purposes.

Whenever a range of the number of atoms in a structure is indicated(e.g., a C₁-C₂₄ alkyl, C₂-C₂₄ alkenyl, C₂-C₂₄ alkynyl, etc.), it isspecifically contemplated that the substituent can be described by anyof the carbon atoms in the sub-range or by any individual number ofcarbon atoms falling within the indicated range. By way of example, adescription of the group such as an alkyl group using the recitation ofa range of 1-24 carbon atoms (e.g., C₁-C₂₄), specifically describes analkyl group having any of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,15, 16, 17, 18, 19, 20, 21, 22, 23 and 24 carbon atoms, as appropriate,as well as any sub-range thereof (e.g., 1-2 carbon atoms, 1-3 carbonatoms, etc.).

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by those working in thefields to which this disclosure pertain.

Before the various embodiments are described, it is to be understoodthat the teachings of this disclosure are not limited to the particularembodiments described, and as such can, of course, vary. It is also tobe understood that the terminology used herein is for the purpose ofdescribing particular embodiments only, and is not intended to belimiting, since the scope of the present teachings will be limited onlyby the appended claims.

As disclosed herein, a number of ranges of values are provided. It isunderstood that each intervening value, to the tenth of the unit of thelower limit, unless the context clearly dictates otherwise, between theupper and lower limits of that range is also specifically disclosed.Each smaller range between any stated value or intervening value in astated range and any other stated or intervening value in that statedrange is encompassed within the invention. The upper and lower limits ofthese smaller ranges may independently be included or excluded in therange, and each range where either, neither, or both limits are includedin the smaller ranges is also encompassed within the invention, subjectto any specifically excluded limit in the stated range. Where the statedrange includes one or both of the limits, ranges excluding either orboth of those included limits are also included in the invention.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this disclosure belongs. Although any methods andmaterials similar or equivalent to those described herein can also beused in the practice or testing of the present teachings, some exemplarymethods and materials are now described.

All patents and publications referred to herein are expresslyincorporated by reference.

As used in the specification and appended claims, the terms “a,” “an,”and “the” include both singular and plural referents, unless the contextclearly dictates otherwise. Thus, for example, “a layer” includes onelayer and plural layers. The term “or” between alternatives includes“and/or”, unless the context clearly dictates that only one alternativecan be present.

In view of this disclosure it is noted that the methods can beimplemented in keeping with the present teachings. Further, the variouscomponents, materials, structures and parameters are included by way ofillustration and example only and not in any limiting sense. In view ofthis disclosure, the present teachings can be implemented in otherapplications and components, materials, structures and equipment toimplement these applications can be determined, while remaining withinthe scope of the appended claims.

EXEMPLARY EMBODIMENTS

To assist in understanding the scope and benefits of the presentinvention, the following description of exemplary or preferredembodiments is provided. The exemplary embodiments should be taken asillustrating, rather than as limiting, the present invention as definedby the claims. As will be readily appreciated, numerous variations andcombinations of the features set forth above can be utilized withoutdeparting from the present invention as set forth in the claims. Suchvariations are not regarded as a departure from the scope of theinvention, and all such variations are intended to be included withinthe scope of the following claims.

-   -   Embodiment 1. A metal anode having a protective coating        comprising a metal layer comprising lithium, sodium, or        potassium; and a protective coating on the metal layer, wherein        the protective coating comprises a composite material, and the        composite material comprises an oxide or fluoride of lithium,        sodium, or potassium.    -   Embodiment 2. The metal anode of embodiment 1, wherein the        composite material comprises lithium fluoride-lithium oxide        (LiF—Li₂O), lithium fluoride-lithium carbonate (LiF—Li₂CO₃),        lithium fluoride-lithium hexafluorophosphate (LiF—LiPF₆),        lithium fluoride-lithium phosphate (LiF—LiPO₄), lithium        fluoride-lithium tetrafluoroborate (LiF—LiBF₄), lithium        fluoride-carbon fluoride (LiF—CF₄), Li₂O—Li₂CO₃, Li₂O—LiF,        Li₂O—LiPO₄, Li₂O—LiBF₄, Li₂O—CF₄, HfO₂, Li_(x)HfO₂, SiO₂,        LiF—NbO₂, Li₃N—AlN, Li_(x)Si₃N₄, Li_(x)Nb₃N₄, or any combination        of these materials.    -   Embodiment 3. The metal anode of embodiment 1, wherein the        composite material comprises (a) a lithium oxide-containing        material when the metal layer comprises lithium; (b) a sodium        oxide-containing material when the metal layer comprises sodium;        or (c) a potassium oxide-containing material when the metal        layer comprises potassium.    -   Embodiment 4. The metal anode of embodiment 3, wherein the        composite material comprises (a) Li₂O—Li₂CO₃, Li₂O—LiF,        Li₂O—LiPO₄, Li₂O—LiBF₄, Li₂O—CF₄, or any combination of these        materials when the metal layer comprises lithium; (b)        Na₂O—Na₂CO₃, Na₂O—NaF, Na₂O—NaPO₄, Na₂O—NaBF₄, Na₂O—CF₄, or any        combination of these materials when the metal layer comprises        sodium, and (c) K₂O—K₂CO₃, K₂O—KF, K₂O—KPO₄, K₂O—KBF₄, K₂O—CF₄,        or any combination of these materials when the metal layer        comprises potassium.    -   Embodiment 5. The metal anode of any of embodiments 1 to 4,        wherein the protective layer comprises HfO₂, M_(x)HfO₂, SiO₂,        MF-M₂O, MF-M₂CO₃, MF-MPF₆, MF-M₃PO₄, MF-MBF₄, MF-CF₄, MF-NbO₂,        M₂O-M₂CO₃, M₂O-MF, M₂O-M₃PO₄, M₂O-MBF₄, M₂O—CF₄, M₃N—AlN,        M₃N—AlN, M_(x)Si₃N₄, M_(x)Nb₃N₄, or any combination thereof,        where X≥1 and M is Li, Na, K, or a mixture thereof.    -   Embodiment 6. The metal anode of any of embodiments 1 to 5,        wherein the metal layer of the metal anode has a thickness of 10        μm to 150 μm.    -   Embodiment 7. The metal anode of any of embodiments 1 to 6,        wherein the protective coating has a thickness from 1 nm to 10        microns.    -   Embodiment 8. The metal anode of any of embodiments 1 to 7,        wherein the protective coating is formed on the metal layer by        atomic layer deposition, plasma enhanced atomic layer        deposition, chemical vapor deposition, plasma enhanced chemical        vapor deposition, sputtering, physical vapor deposition,        spinning coating, dip coating, or pulsed laser deposition.    -   Embodiment 9. A lithium-free metal or carbon electrode for a        lithium ion battery, the electrode comprising: a metal or carbon        layer; a protective coating on the metal layer, wherein the        protective coating include but not limited to aluminum oxide,        titanium oxide, hafnium oxide, zirconium dioxide, lithium oxide,        lanthanum oxide, zinc oxide, antimony tetroxide, antimony        pentoxide, arsenic trioxide, arsenic pentoxide, barium oxide,        bismuth oxide, bismuth oxide, calcium oxide, cerium oxide,        cerium oxide, chromium oxide, chromium oxide, chromium oxide,        chromium oxide, cobalt oxide, cobalt oxide, cobalt oxide, copper        oxide, copper oxide, iron oxide, iron oxide, lead oxide,        magnesium oxide, manganese oxide, mercury oxide, nickel oxide,        rubidium oxide, silicon dioxide, silver oxide, thallium oxide,        thallium oxide, thorium oxide, tin oxide, uranium oxide,        tungsten oxide, selenium dioxide, tellurium dioxide, lithium        sulfide, lithium nitride, lithium nitrate, lithium carbonate,        lithium fluoride, lithium chloride, lithium bromide, lithium        carbide, lithium borate, lithium sulfate, lithium        hexafluorophosphate, lithium hydroxide, lithium tantalite,        lithium iodide, lithium tetrakispentafluorophenyl borate,        yttrium lithium fluoride, polyethylene glycol, gelatin, lithium        hafnium oxide, a lithium fluoride-lithium carbonate composite or        polytetrafluoroethylene, or any combination thereof.    -   Embodiment 9a. An electrode for a lithium ion battery, the        electrode comprising: a metal layer; a protective coating on the        metal layer, wherein the protective coating comprises hafnium        oxide, lithium hafnium oxide, a lithium fluoride-lithium        carbonate composite, or a combination thereof.    -   Embodiment 10. The electrode of embodiment 9 or 9a, wherein the        metal layer is lithium or copper.    -   Embodiment 10a. The electrode of embodiment 9 or 9a, wherein the        metal layer is copper, nickel, titanium, carbon or graphite        layer, tantalum (Ta) foil, tungsten (W) foil, vanadium (V) foil,        or stainless steel or any combination thereof.    -   Embodiment 11. The electrode of embodiment 9 or 9a, wherein the        protective coating is formed by atomic layer deposition or        plasma enhanced atomic layer deposition.    -   Embodiment 11a. The electrode of embodiment 9 or 9a, wherein the        protective coating is formed by atomic layer deposition,        chemical vapor deposition, plasma enhanced chemical vapor        deposition, physical vapor deposition, pulsed laser deposition        or plasma enhanced atomic layer deposition.    -   Embodiment 12. The electrode of embodiment 9 or 9a, wherein the        thickness of the protective coating can range from 0.1        nanometers to 50 microns, with particular interest of the        thickness from 0.5 nm to 10 microns. The metal foil thickness        can range from 0.1 μm to 50 μm.    -   Embodiment 13. A cathode comprising a metal layer having a        surface and comprising a lithium-based material; an inert        material on the surface of the metal layer; wherein the cathode        is configured for use as the cathode of a lithium-ion battery or        lithium-sulfur battery.    -   Embodiment 14. The cathode of embodiment 13, wherein the inert        material comprises a metal, a metal oxide, a metal halide, a        metal oxyfluoride, a metal nitride, a metal carbonate, a metal        sulfide, a metal sulfate, a metal phosphate, a non-metal oxide,        a non-metal carbide, a non-metal, or mixture of any two or more        thereof.    -   Embodiment 15. The cathode of embodiment 13, wherein the inert        material comprises a material selected from the group consisting        of Al, Cu, Al₂O₃, TiO₂, ZnO, La₂O₃, NbO₂, ZrO₂, Li₂O, HfO₂,        GaO₂, GeO₂, CeO₂, MgO, CaO, LiF, AlF₃, LiAlF₄, MgF₂, Zn₂OF₂,        Li₃FO, LiCF₅, Li₃N, TiN, Li₂CO₃, CaCO₃, ZnCO₃, La₂(CO₃)₃, Nb        (CO₃)₂, MgCO₃, Li₂S, ZnS, GaS₂, TiS₂, NbS₂, HfS₂, CaS, La₂S₃,        BaSO₄, Li₃PO₄, AlPO₄, WF₄, W(PO₄)₂, SiO₂, SiC, Si, carbon, or        mixtures of any two or more thereof.    -   Embodiment 16. The cathode of embodiment 13, wherein the metal        layer comprises Li_(X)Ni_(Y)Mn_(Z)Co_(N)O₂ (NMC, X≥1, Y≥0.6,        Z≥0.1, N≥0), Li_(X)Ni_(Y)Mn_(N)O₂ (NMO, X≥1, Y≥0.2, N≥0.2), or        Li_(X)Ni_(Y)Co_(Z)Al_(N)O₂ (NCA, X≥1, Y≥0.6, Z≥0, N≥0.01),        optionally with a dopant.    -   Embodiment 16a. The cathode of embodiment 13, wherein the metal        layer comprises lithium sulfide (Li₂S), and the inert material        comprises a lithium metal oxide (e.g., lithium niobium oxides,        lithium hafnium oxides and lithium lanthanum oxides, etc.),        lithium oxide (Li₂O), lithium phosphate (Li₃PO₄), lithium        silicon oxide, lithium aluminum phosphate (Li_(x)AlPO₄), and        lithium fluoride based materials, including but not limited to        LiF, lithium aluminum fluoride (Li_(x)AlF_(y)), lithium tungsten        aluminum fluoride (Li_(x)WAlF_(y)), lithium fluoride-lithium        oxide (LiF—Li₂O), lithium fluoride-lithium carbonate        (LiF—Li₂CO₃), lithium fluoride-lithium hexafluorophosphate        (LiF—LiPF₆), lithium fluoride-lithium phosphate (LiF—LiPO₄),        lithium fluoride-lithium tetrafluoroborate (LiF—LiBF₄) and        lithium fluoride-carbon fluoride (LiF—CF₄), or any combination        thereof.    -   Embodiment 16b. A battery comprising an electrode (an anode or a        cathode) of any of the foregoing embodiments, and a solid        electrolyte interphase (SEI) formed by or on the protective        coating.    -   Embodiment 17. A process for preparing the cathode of embodiment        13 or other cathode described herein. The process comprises        depositing a thin layer of the inert material onto the surface        of the metal layer by atomic layer deposition, plasma enhanced        atomic layer deposition, chemical vapor deposition, plasma        enhanced chemical vapor deposition, sputtering, physical vapor        deposition, spinning coating, dip coating, or pulsed laser        deposition.    -   Embodiment 18. The process of embodiment 17, further comprising        forming the metal layer from a cathode material powder.    -   Embodiment 19. The process of embodiment 18, wherein the cathode        material powder has a mean particle size from 50 nm to 50 km.    -   Embodiment 20. The process of embodiment 18 or 19, further        comprising forming the cathode material powder by a sol-gel        method, solid state reaction, ultrasonic spray pyrolysis,        flame-assisted pyrolysis, liquid-feed flame spray pyrolysis, or        co-precipitation.    -   Embodiment 21. The process of embodiment 18, 19, or 20, wherein        the cathode material comprises sulfur or lithium sulfide        powders.    -   Embodiment 22. The process of any of embodiments 18 to 21,        further comprising forming the metal layer by mixing the cathode        material with a binder and conductive additives to form a        laminate.    -   Embodiment 22a. The process of embodiment 22, wherein the        cathode material, the binder, and the conductive additivies cast        onto a current collector before forming the laminate.    -   Embodiment 23. The process of embodiment 17, wherein the inert        material is deposited in multiple cycles by atomic layer        deposition or chemical vapor deposition.    -   Embodiment 24. The process of embodiment 17, wherein the inert        material is deposited by depositing inert material precursors.    -   Embodiment 25. The process of embodiment 24, wherein the inert        material precursors are metal organics, and the inert material        is deposited at a temperature from 80° C. to 300° C.    -   Embodiment 26. The process of embodiment 24, wherein the inert        material precursors are inorganic and the inert material is        deposited at a temperature from 500° C. to 1200° C.    -   Embodiment 27. The process of embodiment 24, wherein the inert        material precursors are selected from trimethylaluminum, AlCl₃,        tris-(dimethylamido)aluminum, trialkylaluminum,        trifluoroaluminum, trichloroaluminum, tribromoaluminum, AlMe₂Cl,        AlMe₂OPr, Al(OEt)₃, Al(OPr)₃, ZrCl₃, ZrCl₄, ZrI₄, ZrCp₂Cl₂,        ZrCp₂Me₂, Zirconium tert-butoxide or called Zr(OtBu)₄,        Zr(dmae)₄, Zr(thd)₄, Zr(NMe₂)₄, Zr(NEt₂)₄, Zr(OPr)₂(dmae)₂,        Zr(OtBu)₂(dmae)₂, Zr(NEtMe)₄, ZnCl₂, ZnEt₂, ZnMe₂, Zn(OAc)₂,        SiCl₄, SiCl₃H, SiCl₂H₂, Bis(trimethylsilyl)amine, Si(NCO)₄,        MeOSi(NCO)₃, GeCl₄, MgCp₂, Mg(thd)₂, TiCl₄, TiI₄, Ti(OMe)₄,        Ti(OEt)₄, Ti(OPr)₄, Ti(OPr)₂(dmae)₂, Ti(OBu)₄, or Ti(NMe₂)₄,        tris(iso-propylcyclopentadienyl) lanthanum, La(TMHD)₃, TDMASn,        TDMAHf, HfCl₄, LiOtBu, CO₂, water, oxygen, ozone, hydrogen        fluoride, hydrogen fluoride pyridine, tungsten hexafluoride,        (tert-butylimido)-tris(diethylamino)-niobium or called        tBuN=Nb(NEt₂)₃, tBuN=Nb(NMeEt)₃, H₂S,        bis-(tri-Isopropylcyclopentadienyl)calcium, disilane (Si₂H₆),        silane (SiH₄), monochlorosilane (SiH₃Cl), C₂H₂, CCl₄, CHCl₃, and        mixtures thereof.    -   Embodiment 28. A method of preparing an anode configured for use        in a lithium-ion battery, the method comprising depositing a        coating material on a metal substrate by atomic layer deposition        (ALD), chemical vapor deposition (CVD), plasma enhanced chemical        vapor deposition (PECVD), sputtering, physical vapor deposition        (PVD), plasma enhanced atomic layer deposition (PEALD), spinning        coating, dip coating, pulsed laser deposition (PLD), or any        combination thereof; wherein the coating material is dielectric        and lithium-ion conductive.    -   Embodiment 29. The method of embodiment 28, wherein the metal        substrate comprises copper, nickel, titanium, carbon or        graphite, tantalum, tungsten, vanadium, or stainless steel or        any combination thereof.    -   Embodiment 30. The method of embodiment 28 or 29, wherein the        metal substrate has a thickness of from 0.1 microns to 50        microns.    -   Embodiment 31. The method of any of embodiments 28 to 30,        wherein the coating material comprises aluminum oxide, titanium        oxide, hafnium oxide, zirconium dioxide, lithium oxide,        lanthanum oxide, zinc oxide, antimony tetroxide, antimony        pentoxide, arsenic trioxide, arsenic pentoxide, barium oxide,        bismuth oxide, bismuth oxide, calcium oxide, cerium oxide,        cerium oxide, chromium oxide, chromium oxide, chromium oxide,        chromium oxide, cobalt oxide, cobalt oxide, cobalt oxide, copper        oxide, copper oxide, iron oxide, iron oxide, lead oxide,        magnesium oxide, manganese oxide, mercury oxide, nickel oxide,        rubidium oxide, silicon dioxide, silver oxide, thallium oxide,        thallium oxide, thorium oxide, tin oxide, uranium oxide,        tungsten oxide, selenium dioxide, tellurium dioxide, lithium        sulfide, lithium nitride, lithium nitrate, lithium carbonate,        lithium fluoride, lithium chloride, lithium bromide, lithium        carbide, lithium borate, lithium sulfate, lithium        hexafluorophosphate, lithium hydroxide, lithium tantalite,        lithium iodide, lithium tetrakispentafluorophenyl borate,        yttrium lithium fluoride, polyethylene glycol, gelatin, or        polytetrafluoroethylene, or any combination thereof.    -   Embodiment 32. The method of any of embodiments 28 to 30,        wherein the coating material comprises lithium phosphorus        oxynitride (LiPON), Li₃YCl₆, Li₃YBr₆, Li₉S₃N,        Li_(1+x)Al_(x)Ge_(y)Ti_(2−x−y)(PO₄)₃(0≤x≤0.8; y=0.8, 1.0),        Li₇La₃Zr₂O₁₂, Al-doped Li₇La₃Zr₂O₁₂, Li(NH₃)_(n)BH₄ (0<n≤2),        LiCoO₂, LiMn₂O₄, LiFePO₄, Li₁₄ZnGe₄O₁₆, lithium lanthanum        titanate, Li₁₀GeP₂S₁₂, Li_(1+x)Ge_(2−y)Al_(y)P₃O₁₂, Li₈S₉P₂,        Li₃FCO₃ or any combination thereof.    -   Embodiment 33. The method of any of embodiments 28 to 32,        wherein the thickness of the coating material is from 0.1        nanometers to 50 microns.    -   Embodiment 34. The method of any of embodiments 28 or 30 to 33,        wherein the metal substrate is a metal foil comprising copper,        nickel, or stainless steel, and the method comprises treating        the metal foil to remove oxide and organic residue before        depositing the coating material.    -   Embodiment 35. A method of preparing a thin layer comprising        lithium, the method comprising a) applying one or more        interlayer material onto a substrate to form an interlayer        material coated substrate; b) heating the interlayer material        coated substrate to an elevated temperature; and c) applying one        or more metal layers onto the interlayer material coated        substrate, wherein the metal layer comprises lithium.    -   Embodiment 36. The method of embodiment 35, wherein the        interlayer material comprises aluminum metal, tin metal, indium        metal, zinc metal, nickel metal, molybdenum metal and titanium        metal, or any metal oxide or metal nitride, such as Al₂O₃, CuO,        ZnO, TiO₂, HfO₂, aluminum nitride (AlN), Li₂O, SiO₂, NbO₂,        Fe₂O₃, Fe₃O₄, FeO, MnO₂, Li₃N, Li₂CO₃, Si₃N₄ and Nb₃N₄, or any        organic material such as carbonates and esters, or silicon, or        any combination thereof.    -   Embodiment 37. The method of embodiment 35 or 36, wherein the        substrate comprises copper (Cu) foil, nickel (Ni) foil,        stainless steel foil, titanium (Ti) foil, carbon or graphite        clothing, tantalum (Ta) foil, tungsten (W) foil, vanadium (V)        foil, or a polymer film. In some embodiments, the substrate is        configured for use as a current collector of a lithium battery.    -   Embodiment 38. The method of any of embodiments 35 to 37,        wherein the interlayer material has a thickness of 0.1 nm to 50        μm, and the substrate has a thickness of 1.0 μm to 45 μm.    -   Embodiment 39. The method of any of embodiments 35 to 38,        wherein the metal layer has a thickness of from 10 nm to 100        microns.    -   Embodiment 40. The method of any of embodiments 35 to 39,        wherein the elevated temperature is between 100 and 250° C.    -   Embodiment 41. The method of any of embodiments 35 to 40,        wherein the metal layer is applied onto the interlayer material        coated substrate by pressing, rolling, printing or extruding.    -   Embodiment 42. The method of any of embodiments 35 to 41,        wherein the interlayer material is applied to the substrate by        chemical vapor deposition, plasma enhanced chemical vapor        deposition, sputtering, physical vapor deposition, atomic layer        deposition, plasma enhanced atomic layer deposition, spinning        coating, dip coating, pulsed laser deposition, or any        combination thereof.    -   Embodiment 43. The method of any of embodiments 35 to 42,        further comprising peeling the metal layer from the substrate to        provide a substrate-free metal film.    -   Embodiment 44. The method of any of embodiments 35 to 43,        wherein the substrate is a current collector, or wherein the        substrate is configured as a current collector.    -   Embodiment 45. The method of any of embodiments 35 to 44,        wherein the one or more metal layers are applied without being        under vacuum.    -   Embodiment 46. A method of preparing a coated lithium layer, the        method comprising depositing a coating material on a lithium        layer by a roll-to-roll process, extrude printing or 3D        printing.    -   Embodiment 47. The method of embodiment 46, wherein the        depositing comprises spatial atomic layer deposition (SALD) in a        roll-to-roll process.    -   Embodiment 48. The method of embodiment 47, wherein the        roll-to-roll process comprises unspooling the lithium layer from        a first roll, passing the lithium layer through a plurality of        deposition zones, and spooling the coated lithium layer on a        second roll, wherein the plurality of deposition zone comprise        at least a first deposition zone comprising a first coating        material precursor that reacts or decomposes on the lithium        layer, and a second deposition zone comprising a second coating        material precursor that reacts or decomposes on the first        coating material precursor.    -   Embodiment 49. The method of embodiment 48, wherein the first        coating material precursor is tetrakis(dimethylamido)hafnium and        the second coating material precursor is water.    -   Embodiment 50. The method of any of embodiments 46 to 49,        wherein the coating material comprises a metal oxide, a metal        halide, a metal oxyfluoride, a metal nitride, a metal carbonate,        a metal sulfide, a metal sulfate, a metal phosphate, a non-metal        oxide, a non-metal carbide, a carbon material, or a mixture of        any two or more thereof.    -   Embodiment 51. The method of any of embodiments 46 to 49,        wherein the coating material comprises Li₂O, La₂O₃, NbO₂, ZrO₂,        HfO₂, GaO₂, GeO₂, CeO₂, MgO, CaO, Li₃OF, LiF, AlF₃, MgF₂,        Zn₂OF₂, Li₃FO, LiCF₅, Li₃N, TiN, Li₂CO₃, CaCO₃, ZnCO₃,        La₂(CO₃)₃, Nb (CO₃)₂, MgCO₃, Li₂S, ZnS, GaS₂, TiS₂, NbS₂, HfS₂,        CaS, La₂S₃, BaSO₄, Li₃PO₄, AlPO₄, WF₄, W(PO₄)₂, SiC, carbon or a        mixture of any two or more thereof.

EXAMPLES Example 1

In this example, an HfO₂ coating is deposited on a copper substrateusing Atomic Layer Deposition (ALD).

To prepare the HfO₂ coated Cu, copper foils are placed in the ALDreactors at 150° C. 50 cycles of ALD HfO₂, based on the reactions oftetrakis(dimethylamino) hafnium(IV) and water as the precursors, isdeposited onto the Cu substrates. The thickness of HfO₂ is determined byellipsometry, giving a thickness of 68 Å.

The HfO₂ coated Cu were tested as anodes in 2325-type coin cellbatteries. The cathodes used in this test were NMC532 and NMC811, andthe circle electrodes had diameter of ⅝ inch. The separator was Celgard2325 membrane, and the electrolyte was concentrated 2 M lithiumbis(trifluoromethanesulfonyl)imide and 2 M lithiumdifluoro(oxalato)borate in dimethoxyethane.

Performances of the HfO₂-coated Cu-metal anode and the bare Cu-metalanode paired with NMC532 cathodes were tested as follows. As shown inFIG. 1 , the battery is charged and discharged in the first three cyclesat 0.1 C, then 0.2 C was used for following cycles. The battery ofHfO₂-coated Cu (FIG. 1A) shows a very promising result considering thatthere is no lithium on the anode side from the initial point andremained at 80% after about 50 cycles (FIG. 2 ). In comparison, whenbare copper (FIG. 1B) was used as the anode with NMC532, the capacitydecayed quickly, which shows that the battery decays to 80% of thecapacity (the fourth cycle). From the Coulombic efficiency (CE) plottedin FIG. 3A, it is clear that with a very thin HfO₂ (˜7 nm), the resultis so stable and maintained at around 99%; while for the control sampleas shown in the FIG. 3B, the bare copper anode demonstrates a veryunstable performance, which is due to the continuous reactions oflithium with the liquid electrolyte.

Performances of the HfO₂-coated Cu-metal anode and the bare Cu-metalanode paired with NMC811 cathodes were tested as follows in FIGS. 4A, 4Band 4C. As shown in FIG. 4A, the battery is charged and discharged inthe first three cycles at 0.1 C, then 0.33 C was used for discharge and0.1 C was used for charge in the following cycles. The battery ofHfO₂-coated Cu (FIG. 4A) shows a very promising result and remained at80% after about 50 cycles, as presented in FIG. 4B as well. From theenergy density and Coulombic efficiency (CE) plotted in FIG. 4B, it isclear that with a very thin HfO₂ (·7 nm) coated on the copper, theenergy density based on all materials' mass can reach over 500 Wh/kg.The CE is so stable and maintained at around 99.5%; while for thecontrol sample where bare copper was used as the anode with NMC811, asshown in the FIG. 4C, the bare copper anode demonstrates a fastdegradation rate and a very unstable performance for CE, which is due tothe continuous reactions of lithium with the liquid electrolyte.

As for the 5 mAh/cm² NMC cathodes, around 25 microns of lithium strippedor plated upon each charge or discharge. The performance of the CE andenergy density shown in FIG. 4B is very stable, suggesting that nolithium dendrites are presented on the anode surface. It is remarkablethat only 7 nm HfO₂ coating by ALD can accommodate about 50 microns oflithium each cycle and it makes at least 100 cycles by suppressing wellthe dendrite formations.

It should be noted that such high energy density is achieved by NMC,calculated on the mass of electrodes and electrolyte excluding the coincells' pack. It is expected that the present anode can be included in abattery with NMC811 or higher capacity cathodes, to achieve an energydensity of 400 Wh/kg-500 Wh/kg based on cell level.

With a pouch cells testing comprising double-sided NMC811, or highercapacity cathodes in multiple layers, it is contemplated that the resultcan accomplish the energy density of over 600 Wh/kg based on materials'mass and realize 500 Wh/kg at cell level.

Example 2

In this example, a metal anode is made and included in Li-ion batteries(coin cells) having NMC as the cathode. The metal anode comprises alithium metal layer and a protective coating comprising ultrapure ALDhafnium dioxide at a thickness of 8 nm. Batteries were made with thesemetal anodes, with a cathode of NMC811.

As shown in FIG. 5A, the battery is charged and discharged in the firstthree cycles at 0.1 C, then 0.33 C was used for following cycles. Thebattery shows a very promising result by achieving 203 mAh/g based onthe mass of the NMC811 mass and remained at 95% after about 60 cycles,demonstrating that the protected lithium is very stable with no sign oflithium dendrites formed during the process.

In comparison, bare lithium tested in batteries with NMC811 shows veryunstable performance, demonstrated in FIG. 5B, which is because barelithium is not stable in liquid electrolyte and forms a lot of sidereactions. However, after certain cycles forming a thick SEI, thelithium seems to perform fine but finally the battery will fail becausethe dendrites consume all electrolytes or cause a short circuit bypenetrating the separator. Based on the mass and the ratio of theelectrodes as well as lithium as the anode, we calculated the energydensity, presented in FIG. 5C for the full cell (Li|NMC811) based on themass of the electrodes (the cathode and the anode). The energy density,as observed, reaches to 550 Wh/kg in the first three cycles at 0.1 C andretained at 480 Wh/kg after 60 cycles at 0.33 C. The cycling performanceof the HfO₂-protected Li cell, even in a lean condition with only 15 Lelectrolyte, shows remarkable results.

The voltage and the energy density were evaluated changes during thecycles, as displayed in FIG. 6 . The 4th cycle is the first cyclestarting with 0.33 C, and it yields 502 Wh/kg. After 16 cycles, the 20thcycle and the 50th cycle degrades very small, demonstrating energydensity of 500 Wh/kg and 482 Wh/kg, respectively. The remarkablestability of protected lithium compared to the bare lithium suggeststhat the ALD HfO₂ is a promising technology to enable the use of lithiummetal anodes for ultrahigh energy batteries.

Example 3

In this example, a coated Li-metal anode is made and evaluated in Li-ioncoin cell batteries having sulfur as the cathode. The evaluatedperformance is shown in FIG. 9 . The metal anode comprises a lithiummetal layer and a protective coating comprising ultrapure ALD lithiumfluoride well mixed lithium carbonate at a thickness of around 8 nm. Acoated lithium anode was paired with a sulfur cathode in a 2325 coincell. The sulfur cathode has a capacity of about 2.5 mAh/cm² and sulfuraccounts for around 80% in the cathode materials. The diameter of circleelectrodes are ⅝ inch with the ratio of electrolyte volume over sulfurmass equaling to 5.

The battery was charged and discharged in the first three cycles at 0.1C, then 0.33 C was used for following cycles. The battery shows apromising result by achieving 650 mAh/g and nearly 100% even after 120cycles, demonstrating that the protected lithium is very stable with nosign of lithium dendrites formed during the process and retains thecapacity of lithium sulfur batteries well. In comparison, bare lithiumtested in batteries with sulfur cathodes exhibited very poor performance(FIG. 9 ), which is attributed to instability of bare lithium in liquidelectrolyte and formation of side reactions. Also, with cycles, thepolysulfides continue to react on the lithium and this causes thecorrosion of lithium metal.

Example 4

In this example, an ultrathin lithium metal anode is made and includedin Li-ion coin cell battery having NMC811 as the cathode. The metalanode comprises a lithium metal layer on a copper substrate at athickness of around 50 microns.

The lithium layer (i.e., Beltech Lithium in FIG. 10 ) was made by theunique process with treated copper substrates. It had a thickness of 50microns. For comparison, a battery was also made with a commerciallyavailable, mechanically pressed lithium. As shown in FIG. 10 , thebattery is charged and discharged in the first three cycles at 0.1 C,then charged at 0.1 C and discharged at 0.5 C at 55° C. The lithiumbattery showed a very promising result by extending the cycle life ofthe lithium anode by over three times compared to the mechanicallypressed lithium.

FIG. 11 shows SEM images of the Li-coated copper anodes prepared withthe unique process and they show that we can make around 30 micronslithium metal on the copper substrate. The three images demonstrate thatour unique process enables the thickness of 30 microns lithium, thegreat smoothness and excellent edges of the lithium metal on copperfoil.

I claim:
 1. A metal anode having a protective coating comprising: a metal layer; and a protective coating on the metal layer, wherein the protective coating comprises aluminum oxide, titanium oxide, hafnium oxide, zirconium dioxide, lithium oxide, lanthanum oxide, zinc oxide, antimony tetroxide, antimony pentoxide, arsenic trioxide, arsenic pentoxide, barium oxide, bismuth oxide, calcium oxide, cerium oxide, chromium oxide, cobalt oxide, copper oxide, iron oxide, lead oxide, magnesium oxide, manganese oxide, mercury oxide, nickel oxide, rubidium oxide, silicon dioxide, silver oxide, thallium oxide, thorium oxide, tin oxide, uranium oxide, tungsten oxide, selenium dioxide, tellurium dioxide, lithium sulfide, lithium nitride, lithium nitrate, lithium carbonate, lithium fluoride, lithium chloride, lithium bromide, lithium carbide, lithium borate, lithium sulfate, lithium hexafluorophosphate, lithium hydroxide, lithium tantalite, lithium iodide, lithium tetrakispentafluorophenyl borate, yttrium lithium fluoride, polyethylene glycol, gelatin, or polytetrafluoroethylene, or any combination thereof.
 2. The metal anode of claim 1, wherein the metal is lithium or copper.
 3. The metal anode of claim 1, wherein the metal layer consists of lithium.
 4. The metal anode of claim 1, wherein the protective coating comprises polyethylene glycol.
 5. The metal anode of claim 4, wherein the protective coating further comprises aluminum oxide, titanium oxide, hafnium oxide, zirconium dioxide, lithium oxide, lanthanum oxide, zinc oxide, antimony tetroxide, antimony pentoxide, arsenic trioxide, arsenic pentoxide, barium oxide, bismuth oxide, calcium oxide, cerium oxide, chromium oxide, cobalt oxide, copper oxide, iron oxide, lead oxide, magnesium oxide, manganese oxide, mercury oxide, nickel oxide, rubidium oxide, silicon dioxide, silver oxide, thallium oxide, thorium oxide, tin oxide, uranium oxide, tungsten oxide, selenium dioxide, tellurium dioxide, or any combination thereof.
 6. The metal anode of claim 1, wherein the protective coating comprises aluminum oxide, titanium oxide, hafnium oxide, zirconium dioxide, lithium oxide, lanthanum oxide, zinc oxide, antimony tetroxide, antimony pentoxide, arsenic trioxide, arsenic pentoxide, barium oxide, bismuth oxide, calcium oxide, cerium oxide, chromium oxide, cobalt oxide, copper oxide, iron oxide, lead oxide, magnesium oxide, manganese oxide, mercury oxide, nickel oxide, rubidium oxide, silicon dioxide, silver oxide, thallium oxide, thorium oxide, tin oxide, uranium oxide, tungsten oxide, selenium dioxide, tellurium dioxide, or any combination thereof.
 7. The metal anode of claim 1, wherein the protective coating is a combination of aluminum oxide and polyethylene glycol.
 8. The metal anode of claim 1, wherein the protective coating comprises aluminum oxide, hafnium oxide, lithium oxide, or manganese oxide.
 9. The metal anode of claim 1, wherein the protective coating has a thickness from 0.1 nanometers to 50 microns.
 10. The metal anode of claim 9, wherein the protective coating has a thickness from 0.5 nm to 500 nm.
 11. The metal anode of claim 1, wherein the protective coating has a thickness from 0.5 nm to 500 nm.
 12. A method of preparing the metal anode of claim 1, comprising depositing the protective coating on the metal layer.
 13. The method of claim 12, wherein the protective coating is deposited by atomic layer deposition (ALD), chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), sputtering, physical vapor deposition (PVD), plasma enhanced atomic layer deposition (PEALD), spinning coating, dip coating, pulsed laser deposition (PLD), or any combination thereof.
 14. The method of claim 12, wherein the protective coating is deposited by a roll-to-roll process.
 15. The method of claim 12, wherein the protective coating is deposited by spatial atomic layer deposition (SALD) in a roll-to-roll process.
 16. The method of claim 12, wherein the protective coating is deposited by extrude printing or 3D printing. 